Change the hole diameters of the 100 K pots similar to the 20K pots in the MEMS board.
Also 50K pot is almost good but the wide distance between the two large support pins seemed a little small to me. Just to be sure please verify the distance between the two large holes for the support pins with the
50K pot in the piezo board (the piezo 50k is not dual gang but sizes should be the same).